1. Field of the Invention
This invention relates to a sheet feeding apparatus. The apparatus is of the kind which includes a plurality of sheet holders for holding respectively a plurality of stacks of sheets, and a frictional feeder device in a fixed location for top-feeding sheets from any selected one of the stacks.
2. Brief Description of the Prior Art
An apparatus of this general kind is described in U.S. Pat. No. 4,108,427, which is concerned with a sheet feeding apparatus for a copying machine in which sheets from either one of two cassettes are fed by a common feed roller. The cassettes are held in casette receivers which are rigidly secured to a cassette cradle. The cassette cradle is mounted on the machine frame by pivotal links, and may be moved in an arcuate fashion to bring the top sheet in either one of the cassettes into feeding engagement with the feed roller. Throughout the feeding operation and during the change over from one cassette to the other, the cassettes remain in fixed positions relative to one another. In order to re-load a cassette with a fresh supply of sheets, it is removed from the machine, loaded, and replaced in the machine. The cassette has inside it an intermediate plate for supporting the stack of sheets, the plate being spring-urged upwards to maintain the top sheet in the stack in the correct position for feeding.
With a sheet feeding apparatus of the kind just described, it is necessary to provide access to the cassettes so that they can be re-loaded or changed. This is done in U.S. Pat. No. 4,108,427 by allowing substantial portions of the cassettes to protrude out of the side of the machine.
A more compact machine can be provided, without the need for removing cassettes and relocating them in their proper places, by providing sheet trays that do not need to be taken out of the machine like the cassettes described above, but which can be withdrawn, on slides or runners, for re-loading.